A blunder is not a sacrifice
Losing a piece is never easy. When material is counted, your amount of material can predict who will ultimately win the game, of course this isn't always the case. Having material with poor position may render your pieces mute, these pieces are on the board but are ineffective because they fail to occupy space. Sometimes losing pieces are easy, you may decide to trade pieces with your opponent in order to "simplify" the game.
A true sacrifice is well thought out and will pang a good leader. It was Machiavelli who stood by the philosophy that, "the end justifies the means." In chess, and in life, that approach may render short-term gains and long-term suffering and regret. You need men to win the war, so don't cause a bloodbath to get a quick win. The game of chess is full of surprises and when "plan A" fails, you'll need troops to carryout an alternate plan. So be very careful with your army. It's easy to go rouge when you've got a great position, but if and when the tables turn, you may find yourself with a scarce army in enemy territory.